xref: /openbsd/usr.bin/vi/ex/ex_bang.c (revision 771fbea0)
1 /*	$OpenBSD: ex_bang.c,v 1.11 2017/04/18 01:45:35 deraadt Exp $	*/
2 
3 /*-
4  * Copyright (c) 1992, 1993, 1994
5  *	The Regents of the University of California.  All rights reserved.
6  * Copyright (c) 1992, 1993, 1994, 1995, 1996
7  *	Keith Bostic.  All rights reserved.
8  *
9  * See the LICENSE file for redistribution information.
10  */
11 
12 #include "config.h"
13 
14 #include <sys/types.h>
15 #include <sys/queue.h>
16 #include <sys/time.h>
17 
18 #include <bitstring.h>
19 #include <errno.h>
20 #include <limits.h>
21 #include <stdio.h>
22 #include <stdlib.h>
23 #include <string.h>
24 #include <unistd.h>
25 
26 #include "../common/common.h"
27 #include "../vi/vi.h"
28 
29 /*
30  * ex_bang -- :[line [,line]] ! command
31  *
32  * Pass the rest of the line after the ! character to the program named by
33  * the O_SHELL option.
34  *
35  * Historical vi did NOT do shell expansion on the arguments before passing
36  * them, only file name expansion.  This means that the O_SHELL program got
37  * "$t" as an argument if that is what the user entered.  Also, there's a
38  * special expansion done for the bang command.  Any exclamation points in
39  * the user's argument are replaced by the last, expanded ! command.
40  *
41  * There's some fairly amazing slop in this routine to make the different
42  * ways of getting here display the right things.  It took a long time to
43  * get it right (wrong?), so be careful.
44  *
45  * PUBLIC: int ex_bang(SCR *, EXCMD *);
46  */
47 int
48 ex_bang(SCR *sp, EXCMD *cmdp)
49 {
50 	enum filtertype ftype;
51 	ARGS *ap;
52 	EX_PRIVATE *exp;
53 	MARK rm;
54 	recno_t lno;
55 	int rval;
56 	const char *msg;
57 
58 	ap = cmdp->argv[0];
59 	if (ap->len == 0) {
60 		ex_emsg(sp, cmdp->cmd->usage, EXM_USAGE);
61 		return (1);
62 	}
63 
64 	/* Set the "last bang command" remembered value. */
65 	exp = EXP(sp);
66 	free(exp->lastbcomm);
67 	if ((exp->lastbcomm = strdup(ap->bp)) == NULL) {
68 		msgq(sp, M_SYSERR, NULL);
69 		return (1);
70 	}
71 
72 	/*
73 	 * If the command was modified by the expansion, it was historically
74 	 * redisplayed.
75 	 */
76 	if (F_ISSET(cmdp, E_MODIFY) && !F_ISSET(sp, SC_EX_SILENT)) {
77 		/*
78 		 * Display the command if modified.  Historic ex/vi displayed
79 		 * the command if it was modified due to file name and/or bang
80 		 * expansion.  If piping lines in vi, it would be immediately
81 		 * overwritten by any error or line change reporting.
82 		 */
83 		if (F_ISSET(sp, SC_VI))
84 			vs_update(sp, "!", ap->bp);
85 		else {
86 			(void)ex_printf(sp, "!%s\n", ap->bp);
87 			(void)ex_fflush(sp);
88 		}
89 	}
90 
91 	/*
92 	 * If no addresses were specified, run the command.  If there's an
93 	 * underlying file, it's been modified and autowrite is set, write
94 	 * the file back.  If the file has been modified, autowrite is not
95 	 * set and the warn option is set, tell the user about the file.
96 	 */
97 	if (cmdp->addrcnt == 0) {
98 		msg = NULL;
99 		if (sp->ep != NULL && F_ISSET(sp->ep, F_MODIFIED)) {
100 			if (O_ISSET(sp, O_AUTOWRITE)) {
101 				if (file_aw(sp, FS_ALL))
102 					return (0);
103 			} else if (O_ISSET(sp, O_WARN) &&
104 			    !F_ISSET(sp, SC_EX_SILENT))
105 				msg = "File modified since last write.";
106 		}
107 
108 		/* If we're still in a vi screen, move out explicitly. */
109 		(void)ex_exec_proc(sp,
110 		    cmdp, ap->bp, msg, !F_ISSET(sp, SC_EX | SC_SCR_EXWROTE));
111 	}
112 
113 	/*
114 	 * If addresses were specified, pipe lines from the file through the
115 	 * command.
116 	 *
117 	 * Historically, vi lines were replaced by both the stdout and stderr
118 	 * lines of the command, but ex lines by only the stdout lines.  This
119 	 * makes no sense to me, so nvi makes it consistent for both, and
120 	 * matches vi's historic behavior.
121 	 */
122 	else {
123 		NEEDFILE(sp, cmdp);
124 
125 		/* Autoprint is set historically, even if the command fails. */
126 		F_SET(cmdp, E_AUTOPRINT);
127 
128 		/*
129 		 * !!!
130 		 * Historical vi permitted "!!" in an empty file.  When this
131 		 * happens, we arrive here with two addresses of 1,1 and a
132 		 * bad attitude.  The simple solution is to turn it into a
133 		 * FILTER_READ operation, with the exception that stdin isn't
134 		 * opened for the utility, and the cursor position isn't the
135 		 * same.  The only historic glitch (I think) is that we don't
136 		 * put an empty line into the default cut buffer, as historic
137 		 * vi did.  Imagine, if you can, my disappointment.
138 		 */
139 		ftype = FILTER_BANG;
140 		if (cmdp->addr1.lno == 1 && cmdp->addr2.lno == 1) {
141 			if (db_last(sp, &lno))
142 				return (1);
143 			if (lno == 0) {
144 				cmdp->addr1.lno = cmdp->addr2.lno = 0;
145 				ftype = FILTER_RBANG;
146 			}
147 		}
148 		rval = ex_filter(sp, cmdp,
149 		    &cmdp->addr1, &cmdp->addr2, &rm, ap->bp, ftype);
150 
151 		/*
152 		 * If in vi mode, move to the first nonblank.
153 		 *
154 		 * !!!
155 		 * Historic vi wasn't consistent in this area -- if you used
156 		 * a forward motion it moved to the first nonblank, but if you
157 		 * did a backward motion it didn't.  And, if you followed a
158 		 * backward motion with a forward motion, it wouldn't move to
159 		 * the nonblank for either.  Going to the nonblank generally
160 		 * seems more useful and consistent, so we do it.
161 		 */
162 		sp->lno = rm.lno;
163 		if (F_ISSET(sp, SC_VI)) {
164 			sp->cno = 0;
165 			(void)nonblank(sp, sp->lno, &sp->cno);
166 		} else
167 			sp->cno = rm.cno;
168 	}
169 
170 	/* Ex terminates with a bang, even if the command fails. */
171 	if (!F_ISSET(sp, SC_VI) && !F_ISSET(sp, SC_EX_SILENT))
172 		(void)ex_puts(sp, "!\n");
173 
174 	/*
175 	 * XXX
176 	 * The ! commands never return an error, so that autoprint always
177 	 * happens in the ex parser.
178 	 */
179 	return (0);
180 }
181